Capt. Joshua Smith, public affairs officer for Marine Corps Installations East, Camp Lejeune, Jacksonville, comments on the recent shooting Tuesday April 8, 2014 at Camp Lejeune. A Marine posted at the main gate of the North Carolina base shot and killed a colleague inside a guard shack Tuesday, a military spokesman said. (AP Photo/John Althouse/The Daily News) (The Associated Press)

CAMP LEJEUNE, N.C. – The father of the 21-year-old Marine killed in an accidental shooting says his son overcame physical hurdles to join his two other brothers in the Marine Corps.

Aubrey Boterf says his son, Lance Cpl. Mark N. Boterf, was born in Amory, Miss., but moved to Crowley, Texas, in 2012 along with his nine siblings.

ADVERTISEMENT

ADVERTISEMENT

His twin brother, Michael Stephen, also a Marine, says Mark underwent surgery to correct a hernia and then pushed himself to quickly meet the Corps* physical standards.

A Pentagon spokesman says the fatal shooting Tuesday by a colleague in a guard shack at the North Carolina base appears to have been an accident. Boterf joined the Marines in 2012, had no deployment history and was on temporary assignment as a sentry.